全文获取类型
收费全文 | 5242篇 |
免费 | 419篇 |
国内免费 | 326篇 |
专业分类
化学 | 209篇 |
晶体学 | 2篇 |
力学 | 25篇 |
综合类 | 139篇 |
数学 | 5320篇 |
物理学 | 292篇 |
出版年
2024年 | 16篇 |
2023年 | 101篇 |
2022年 | 165篇 |
2021年 | 131篇 |
2020年 | 204篇 |
2019年 | 224篇 |
2018年 | 218篇 |
2017年 | 203篇 |
2016年 | 125篇 |
2015年 | 90篇 |
2014年 | 178篇 |
2013年 | 442篇 |
2012年 | 193篇 |
2011年 | 296篇 |
2010年 | 303篇 |
2009年 | 449篇 |
2008年 | 386篇 |
2007年 | 275篇 |
2006年 | 315篇 |
2005年 | 215篇 |
2004年 | 197篇 |
2003年 | 169篇 |
2002年 | 162篇 |
2001年 | 150篇 |
2000年 | 139篇 |
1999年 | 136篇 |
1998年 | 115篇 |
1997年 | 76篇 |
1996年 | 49篇 |
1995年 | 52篇 |
1994年 | 40篇 |
1993年 | 27篇 |
1992年 | 25篇 |
1991年 | 15篇 |
1990年 | 12篇 |
1989年 | 15篇 |
1988年 | 15篇 |
1987年 | 9篇 |
1986年 | 4篇 |
1985年 | 12篇 |
1984年 | 12篇 |
1983年 | 3篇 |
1982年 | 10篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 3篇 |
1974年 | 2篇 |
排序方式: 共有5987条查询结果,搜索用时 46 毫秒
141.
Marién Abreu Jan Goedgebeur Domenico Labbate Giuseppe Mazzuoccolo 《Journal of Graph Theory》2019,92(4):415-444
A -bisection of a bridgeless cubic graph is a -colouring of its vertex set such that the colour classes have the same cardinality and all connected components in the two subgraphs induced by the colour classes ( monochromatic components in what follows) have order at most . Ban and Linial Conjectured that every bridgeless cubic graph admits a -bisection except for the Petersen graph. A similar problem for the edge set of cubic graphs has been studied: Wormald conjectured that every cubic graph with has a -edge colouring such that the two monochromatic subgraphs are isomorphic linear forests (ie, a forest whose components are paths). Finally, Ando conjectured that every cubic graph admits a bisection such that the two induced monochromatic subgraphs are isomorphic. In this paper, we provide evidence of a strong relation of the conjectures of Ban-Linial and Wormald with Ando's Conjecture. Furthermore, we also give computational and theoretical evidence in their support. As a result, we pose some open problems stronger than the above-mentioned conjectures. Moreover, we prove Ban-Linial's Conjecture for cubic-cycle permutation graphs. As a by-product of studying -edge colourings of cubic graphs having linear forests as monochromatic components, we also give a negative answer to a problem posed by Jackson and Wormald about certain decompositions of cubic graphs into linear forests. 相似文献
142.
Let m ≤ n ≤ k. An m × n × k 0‐1 array is a Latin box if it contains exactly m n ones, and has at most one 1 in each line. As a special case, Latin boxes in which m = n = k are equivalent to Latin squares. Let be the distribution on m × n × k 0‐1 arrays where each entry is 1 with probability p, independently of the other entries. The threshold question for Latin squares asks when contains a Latin square with high probability. More generally, when does support a Latin box with high probability? Let ε > 0. We give an asymptotically tight answer to this question in the special cases where n = k and , and where n = m and . In both cases, the threshold probability is . This implies threshold results for Latin rectangles and proper edge‐colorings of Kn,n. 相似文献
143.
《Discrete Mathematics》2019,342(10):2846-2849
144.
In Korchmáros et al. (2018)one-factorizations of the complete graph are constructed for with any odd prime power such that either or . The arithmetic restriction is due to the fact that the vertices of in the construction are the points of a conic in the finite plane of order . Here we work on the Euclidean plane and describe an analogous construction where the role of is taken by a regular -gon. This allows us to remove the above constraints and construct one-factorizations of for every even . 相似文献
145.
146.
A graph with at least vertices is said to be distance -extendable if, for any matching of with edges in which the edges lie at distance at least pairwise, there exists a perfect matching of containing . In this paper we prove that every 5-connected triangulation on the projective plane of even order is distance 3 7-extendable and distance 4 -extendable for any . 相似文献
147.
148.
149.
150.